In the field of vacuum technology, especially thin layer technology, the coating of substrates, for example, compact disks (CD) is known. Compact disks are a modern storage medium for digital information. In a sputtering process, the pressed plastic disks are coated with an aluminum layer, for example, which has a thickness of less than one ten-thousandth of a millimeter. The sputtering apparatuses used for this purpose have an annular configuration. A robot discharges the apparatus via a lock chamber in a clean room. From the lock, a substrate carrier transports the substrates across the annular process chamber. The sputtering is carried out by a high performance sputtering cathode which is designed as a magnetron.
An apparatus of this type is described, for example, in DE 39 12 295 by Leybold AG. This known cathode sputtering system is used for one-sided coating with a laser-reflecting aluminum layer. The apparatus comprises a cylindrical, vertically disposed vacuum chamber with a feeding and discharging station, a high performance sputtering cathode, a transport ring for receiving disks, and dynamic locks for pressure separation between the coating chamber and the feeding/discharging station.